#!/bin/bash

# -------------------------------------------------------------------------- #
# Copyright 2002-2023, OpenNebula Project, OpenNebula Systems                #
#                                                                            #
# Licensed under the Apache License, Version 2.0 (the "License"); you may    #
# not use this file except in compliance with the License. You may obtain    #
# a copy of the License at                                                   #
#                                                                            #
# http://www.apache.org/licenses/LICENSE-2.0                                 #
#                                                                            #
# Unless required by applicable law or agreed to in writing, software        #
# distributed under the License is distributed on an "AS IS" BASIS,          #
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   #
# See the License for the specific language governing permissions and        #
# limitations under the License.                                             #
#--------------------------------------------------------------------------- #

# clone fe:SOURCE host:remote_system_ds/disk.i size
#   - fe is the front-end hostname
#   - SOURCE is the path of the disk image in the form DS_BASE_PATH/disk
#   - host is the target host to deploy the VM
#   - remote_system_ds is the path for the system datastore in the host

SRC=$1
DST=$2
VM_ID=$3
DS_ID=$4

if [ -z "${ONE_LOCATION}" ]; then
    TMCOMMON=/var/lib/one/remotes/tm/tm_common.sh
else
    TMCOMMON=$ONE_LOCATION/var/remotes/tm/tm_common.sh
fi

DRIVER_PATH=$(dirname $0)

source $TMCOMMON
source ${DRIVER_PATH}/../../datastore/libfs.sh
source ${DRIVER_PATH}/../../etc/tm/fs_lvm/fs_lvm.conf

#-------------------------------------------------------------------------------
# Set dst path and dir
#-------------------------------------------------------------------------------

DST_PATH=`arg_path $DST`
DST_HOST=`arg_host $DST`
DST_DIR=`dirname $DST_PATH`

SRC_ARG_PATH=`arg_path $SRC`

DST_DS_PATH="$(dirname $(dirname $(dirname $DST_PATH)))"
SRC_DS_PATH="$(dirname $(dirname $SRC_ARG_PATH))"

SRC_PATH="${DST_DS_PATH}${SRC_ARG_PATH##$SRC_DS_PATH}"

DS_SYS_ID=$(echo $DST_DIR | $AWK -F '/' '{print $(NF-1)}')

disable_local_monitoring $DST_HOST $DST_DIR

#-------------------------------------------------------------------------------
# Get Image information
#-------------------------------------------------------------------------------

DISK_ID=$(basename ${DST_PATH} | cut -d. -f2)

XPATH="${DRIVER_PATH}/../../datastore/xpath.rb --stdin"

unset i j XPATH_ELEMENTS

while IFS= read -r -d '' element; do
    XPATH_ELEMENTS[i++]="$element"
done < <(onevm show -x $VM_ID| $XPATH \
                    /VM/TEMPLATE/DISK[DISK_ID=$DISK_ID]/SIZE \
                    /VM/TEMPLATE/DISK[DISK_ID=$DISK_ID]/ORIGINAL_SIZE \
                    /VM/HISTORY_RECORDS/HISTORY[last\(\)]/TM_MAD)

SIZE="${XPATH_ELEMENTS[j++]}"
ORIGINAL_SIZE="${XPATH_ELEMENTS[j++]}"
TM_MAD="${XPATH_ELEMENTS[j++]}"

# Remove potential " and ' chars to avoid bash syntax errors on ssh command below.
FILE_TYPE=`file --brief ${SRC_PATH} | tr -d \"\'`
FILE_SIZE=`fs_size "${SRC_PATH}" YES`

if [ $? -ne 0 ]; then
    FILE_SIZE=0
fi

if [ $FILE_SIZE -gt $SIZE ]; then
    SIZE="$FILE_SIZE"
fi

# Extend the SIZE so the encrypted file fits in the LV
if [[ "$FILE_TYPE" =~ "LUKS encrypted file" ]]; then
    SIZE=$(( SIZE + 4 ))
fi

# Compute the seek start for zeroing of the new LV as the smaller
# number of ONE or file image virtual size. We start to zero from
# 1 MiB before the end of image size prior to the copying.
if [ "${FILE_SIZE}" -lt "${SIZE}" ]; then
    ZERO_SEEK_BYTES=$FILE_SIZE
else
    ZERO_SEEK_BYTES=$SIZE
fi

if [ "${ZERO_SEEK_BYTES}" -gt 0 ]; then
    ZERO_SEEK_BYTES=$(( (ZERO_SEEK_BYTES-1) * 1024 * 1024 ))
else
    ZERO_SEEK_BYTES=0
fi

#-------------------------------------------------------------------------------
# Create the snapshot and link it
#-------------------------------------------------------------------------------

LV_NAME="lv-one-$VM_ID-$DISK_ID"
VG_NAME="vg-one-$DS_SYS_ID"
DEV="/dev/${VG_NAME}/${LV_NAME}"

# Execute lvcreate with a lock in the frontend
CREATE_CMD=$(cat <<EOF
    set -e -o pipefail
    $SYNC
    $SUDO $LVSCAN
    $SUDO $LVCREATE --wipesignatures n -L${SIZE}M -n $LV_NAME $VG_NAME
EOF
)

LOCK="tm-fs_lvm-${DS_SYS_ID}.lock"
exclusive "${LOCK}" 120 ssh_exec_and_log "$DST_HOST" "$CREATE_CMD" \
        "Error creating LV named $LV_NAME"

CLONE_CMD=$(cat <<EOF
    set -e -o pipefail
    mkdir -p $DST_DIR

    hostname -f >"${DST_DIR}/.host" || :

    # zero trailing space
    if [ "${ZERO_LVM_ON_CREATE}" = "yes" ]; then
    LVSIZE=\$(${SUDO} ${LVS} --nosuffix --noheadings --units B -o lv_size "${DEV}" | tr -d '[:blank:]')
    ${DD} if=/dev/zero of="${DEV}" bs=${DD_BLOCK_SIZE:-64k} \
        oflag=seek_bytes iflag=count_bytes \
        seek="${ZERO_SEEK_BYTES}" count="\$(( LVSIZE - ${ZERO_SEEK_BYTES} ))"
    fi

    if [[ '$FILE_TYPE' =~ "LUKS encrypted file" ]]; then
        cat "$SRC_PATH" > "$DEV"
    else
        $QEMU_IMG convert -O raw "$SRC_PATH" "$DEV"
    fi

    rm -f "$DST_PATH"
    ln -s "$DEV" "$DST_PATH"
EOF
)

ssh_exec_and_log "$DST_HOST" "$CLONE_CMD" \
        "Error cloning $SRC_PATH to $LV_NAME"

exit 0
